Interesting Read on Mini14 Accuracy by Ed Harris....

Discussion in 'Firearms' started by BTPost, Mar 2, 2011.


  1. BTPost

    BTPost Old Fart Snow Monkey Moderator

    I do not know if this has been posted here before, but I find this an excellent treatise on Mini14 Accuracy from an ex-Ruger Engineer....


    From: "Ralph Mowery" and Posted on rec.guns Newsgroup

    I have had one of the Ranch rifle versions for a good many years. It is not
    accurate. I know the scope is good ( 4 to 12 variable) because I had it on
    a 22/250 for a while and it would shoot less than 1 inch. Here is something
    about the Ruger and what to exect from them. I wish that I had bought an AR
    type when I got that Ruger. I now have an AR and it is so much beter.

    From: ED HARRIS Refer#: NONE
    Subj: Bedding Conf: (11) F-Firearms
    ---------------------------------------------------------------------------


    My Observations on the Ruger Mini-14

    By Ed Harris Rev. 5-25-94

    When I was at Ruger I tested hundreds of Mini 14 rifles of all
    configurations, conducting audit shoots of normal production, as
    well as R&D testing of the full-auto AC556, AC556 and the experi-
    mental XGI rifle in .308 Win, and assisting in the development of
    the Mini Thirty in 7.62x39.

    To be COMPLETELY honest I was disappointed with its accuracy when
    compared to the M16A1 and A2 rifles, with which I am very familiar.
    The Mini 14 gives reasonable performance for an American-made rifle
    in its price range, and is safe, serviceable and realiable. It just
    isn't all that accurate. You can find individual rifles which shoot
    well, but these are statistical aberrations. We tried to test a large
    enough sample of rifles to pick "good" ones, then painstakingly took
    them apart and gaged every part to see if we could tweak tolerances or
    make design changes which would significantly improve accuracy without
    increasing production cost. It couldn't be done. We did learn a few
    things, however.

    The long run average group size for standard Mini-14 rifles fired
    from a test stand is about 4-5" for ten-shot groups with M193 or M855
    ammunition of "average" quality, producing an acceptance Mean Radius
    of 1.6-1.6" at 200 yds from a test barrel. The M16A1 or A2 do this
    at 200 yards from a machine rest. I believe the biggest factor in
    Mini-14 accuracy is irregular contact between the gas block and the
    face of the slideblock, welded to the slide handle (aka operating rod).

    If you disassemble the rifle and inspect the face of the slide block
    and the rear of ther gas block assembly, you may find that the face of
    the slide block strikes one side or the other of the gas block, rather
    than making a uniform and symmetrical imprint. This asymmetrical
    contact causes fliers. The fit-up can sometimes be improved by
    grinding 0.005-.010" off the face of the slide, so that with the slide
    fully forward, a .001" shim can be inserted between the slide block
    and gas block and be clear all the way around. This way the forward
    motion of the slide is stopped by the right locking lug in the cam
    pocket of the slide handle, rather than by the slide block slamming
    against the gas block, as is the case with the M1 Garand rifle.

    I caution against removing the gas block, because these are installed
    in a fixture at the factory to insure proper alignment. There is a
    small bushing in the gas block which locates it on the barrel. You
    must be careful not to lose this. This is why the gas block screws
    are staked in place on newer guns.

    The condition of the muzzle crown is important as well as the
    straightness of the barrel. Sometimes the barrels are bent when
    pressing the front sight on. Usually they catch this at the factory
    and they correct them if it causes fliers in the range, but since they
    only shoot indoors at 50 yards, for a 2" group, the accuracy
    standards are more in keeping for a plinking rifle than for the
    serious accuracy enthusiast.

    The Mini-14 chamber conforms to U.S. dwg. #8448649, which is used for
    the M16A1 chamber. It has a .225" cylindrical ball seat with a slight
    freebore. I do not believe the GI chamber causes any inaccuracy in
    this type of rifle, because I have fired thousands of rounds in heavy
    test barrels with this chamber which gave fine accuracy. For an
    accuracy load I suggest 21-22 grs. of 4198 (either IMR or Hodgdon)
    with the 52 or 53-gr. Sierra bullets loaded to 2.25" OAL, or 23-23.5
    grs. of H322. The 52-gr. Nosler solid base also is quite accurate.

    The Mini-14 Ranch Rifle was made in .222 Remington for the export
    market to France, Belgium and Italy where civilians are not allowed to
    own firearms of military caliber. Overruns were sold in the U.S.
     
  2. Hispeedal2

    Hispeedal2 Nay Sayer

    Interesting read.
     
  3. Mountainman

    Mountainman Großes Mitglied Site Supporter+++

    If you want to buy one that is accurate you need to go to the newer target model. Bought one for the wife and put a Nikon 3x9 scope on it. We sighted it in with cheap Rem UMC ammo and did not have a problem getting 1" MOA. Kind of a strange looking rifle, but the accuracy it there.
    Ruger Mini-14 Target Rifle.
     
  4. jungatheart

    jungatheart Beginner's Mind

    I owned one and loved the way it looked with folding stock but it wouldn't shoot worth a damn. Couldn't afford an expensive door stop so I sold it.
     
  5. hummerdriver81

    hummerdriver81 Monkey+

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